Saying "nice haircut" in a sarcastic and snide way is an example of a comment that would be described as snarky.
A person who hates traveling who is packing to go on a trip and who is complaining about it every step of the way is an example of someone who is snarky.
Origin of snarky
- From dialectal snark to nag from snark, snork to snore, snort from Dutch and Low German snorken of imitative origin
From American Heritage Dictionary of the English Language, 5th Edition